Black azo dye.



UNITE MARTIN HERZBERG, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBEN- FABRIKEN OF ELBERFELD GO, OF NEW YORK, N. Y., A CORPORATION OF NEIV YORK.

BLMCl fi AZO DYE.

Specification of Letters Patent.

Patented Aug. 22, 1905.

To all whom it may concern.-

Be it known that I, MARTIN HERZBERG, doctor of philosophy, chemist, (assignor to the FARBENFABRIKEN o1 ELBERFELD COMPANY, of New York,) residing at Elberfeld, Germany, have invented a new and useful Improvement in Black Azo Coloring-Matters; and I hereby declare the following to be a clear and exact description of my invention.

I have found that new and valuable azo dyestuffs are obtained by first combining the diazo compounds obtainable from mononitroacefyl-paraphenylenediamin having the formu a with alkylamidonaphthol disulfonic acids, and then splitting off from the resulting dyestuffs the acetyl group by saponification. By the term alkylamidonaphthol disulfonic acids Idenote amidonaphthol disulfonic acids which are substituted in the amido group by alkyls or aryls, such as methyl, phenyl, benzyl, dinitrophenyl, the glycin group, or the like.

The new dyestuifs are in the shape of their alkaline salts dark powders soluble in Water. They yield upon suitable reduction with stannous chlorid and hydrochloric acid triamidobenzene and amidoalkylamidonaphthol disulfonic acids. They dye unmordanted wool from acid-baths black shades.

In carrying out my process practically I can proceed as follows, the parts being by Weight: 19.5 parts of inononitroacetyl-paraphenylenediamin having the above-given formula are diazotized in the usual manner by means of hydrochloric acid and seven parts of sodium nitrite, and the resulting diazo compound is added to a solution of 39.5 parts of the sodium salt of l-ethylamido-S-naphthol- 3.6-disulfonic acid containing an excess of sodium carbonate. It is stirred until the formation of the dyestuff is completed. \(Vhen this point is reached, the dyestufi' is precipitated by the addition of common salt, filtered off and dried. It dyes wool from acid-baths Violet-red shades. The coloring-matter thus obtained is then heated to boiling with eight times its quantity of a fifty-per-cent. sulfuric acid in order to split off the acetylgroup. The new azo dyestuff thus produced deposits during the heating in a crystalline shape. It dyes unmordanted wool black shades.

The isolation of the intermediate product is not necessary. The acetyl group can also be split off by directly boiling the reaction mass with acids or alkalies.

The process proceeds in an analogous man nor on using other alkylamidonaphthol disulfonic acids, such as the glycin of the 1-8-amidononaphthol disulfonie acid, the 1-benzylamido-8-naphthol-3-(S-disulfonic acid, l-alkylamido-S-naphthol- LG-disulfonic acids, l-alkylamido-5-naphthol-2.'T-disulfonic acids, 2- alkylamido-8-naphthol-. 6-disulfonic acids, or the like.

The new dyestuif obtained according to the above-given example is in the shape of its sodium salt a black powder soluble in water with a blue color and soluble in concentrated sulfuric acid of 66 Baum with a red color. It yields upon reduction with staunous chlorid and hydrochloric acid triamidobenzene and the i-oxy-2-amido-8-ethylamidonaphthaleue- 3. 6-disulfonie acid and dyes unmordanted wool black shades.

Having now described my invention and in what manner the same is to be performed, what I claim as new, and desire to secure by Letters Patent, is

1. The hereiu-described new azo dyestuffs obtainable by first con'ibining the diazo compound of mononitroacetyl-paraphenylene diamiu having the above-given formula with alkylamidonaphthol disulfonic acids and then splitting off the acetyl group by saponilication, which dyestull's are in the shape of their alkaline salts dark powders soluble in water; dyeing umnordanted wool black shades; and yielding upon reduction with stannous chlorid and hydrochloric acid triamidobenzene and amide alkylamidonaphthol disulfonic acids, substantially as hereinbefore described.

2. The herein-described new azo dyestufl' obtainable by lirst'combining the diazotized mononitroacetyl paraphenylenediamin having the above-given formula with l-ethylamido-8-naphthol-3.6-disulfonic acid and then splitting oil the acetyl group by sapouilication, Which dyestuif is in the shape of its sosulfonic acid, substantially as hereinbefore dium salt a dark powder soluble in Water with described.

a blue color. being dissolved by concentrated In testimony whereofIhave signed my name sulfuric acid of 66 Baum With a red color; in the presence of two subscribing Witnesses.

dyeing unmordanted WOOl black shades; and MARTIN HERZBERG. yielding upon reduction With stannous chlorid l/Vitnesses: v and hydrochloric acid triamidobenzene and 1- OTTO KONIG,

oxy-Q-amidO-S-ethylamidonaphthalene 3.6-di- J. A. RITTERSHAUS. 

